Evolution is often considered to be an almost imperceptibly slow process. However, the cells that compose our own bodies are constantly acquiring mutations. Some of these mutations may influence cellular phenotypes, such as growth, resulting in clonal expansions. Over time the body may become a patchwork of clones. These processes may have profound implications for cancer progression and ageing. Due to technical limitations this evolutionary landscape has remained almost totally unexplored. I work with laser capture microdissection and genome sequencing to describe and understand processes of somatic evolution. I seek to adapt methods from comparative evolutionary genomics to gain new insights into evolution within the body.